PB2464: STRATIFICATION AND IMMUNOLOGIC ANALYSIS OF PATIENTS WITH SARS-COV-2 INFECTION AFTER HEMATOPOIETIC STEM CELL TRANSPLANTATION
Authors: Man Chen, Hui Wang
Journal: HemaSphere (2023)

Topic: 22. Stem cell transplantation - Clinical Background: In Dec. 2022, Beijing was hit by the Omicron epidemic. The patients after allogeneic hematopoietic stem cell transplantation(allo-HSCT) need special care in the epidemic for the low immunity. According to the “Diagnosis and Treatment Plan for Covid-19 Infection (Trial Version 10)” issued by Chinese government, we classified the patients who clinically caught COVID-19 after allo-HSCT and analyzed the immune status of the infection course. Aims: Analyse the effect of COVID-19 to immune function of patients after allo-HSCT. Methods: A total of 47 patients who caught COVID-19 after allo-HSCT were studied from Dec. 2022 to Jan. 2023 in Beijing Lu Daopei Hospital, including 23 males and 24 females, of which 30 cases were mild condition, 11 medium, 6 severe, and no critical cases. The median age was 33 (12, 44) years old. Flow cytometry was used to analyze the changes of immune subsets and cytokines in the patients before and after covid-19. All data were processed by SPSS 23.0. Results: 1. There was no significant difference in whether vaccination(P=0.345), GVHD status when infection(P=0.432) and decreased hemogram(P=0.346) among mild, moderate, and severe groups. Patients with low blood oxygen saturation increased with severity(0/30, 1/11, and 6/6, respectively,P<0.001). So did the patients with pneumonia (0/30, 8/11, and 6/6, respectively, P<0.001). The interval between transplantation and infection of covid-19 was 234 (90.5-459) days in mild patients, which was greater than 174.00 (94-190) days of moderate group and 174.50 (56.5-285.5) days of severe group patients, but the difference did not reach significance. The number of days for severe cases to turn negative in the covid-19 nucleic acid test was longer than that of the moderate and mild groups (P=0.024).2. The level of CRP (P=0.001), PCT (P=0.005), and IL-6 (P=0.041) of patients in the severe group were significantly higher than those of the other two groups after covid-19. There were no significant differences in CT values, IgG, IgA, and IgM levels in three groups at the time of infection (P=0.302, P=0.264, P=0.310, P=0.715).3. The immune function before the covid-19 infection may be poor for severe patients, but the immune reserve capacity remain strong, which may be related to the recovery after infection (see Table 1). The absolute counts of CD3, CD4, and CD8-positive T cells, B cells, and NK cells (units/microliter) in the severe group were lower than those in the moderate and mild groups, but the difference among the three groups did not reach statistical significance by K-W test (P=0.594, P=0.520, P=0.518, P=0.665, P=0.203) which maybe due to the low number of cases. In addition, the percentages of central memory T cells (TCM) and naive T cells (NaiveT) in severe patients were higher than those in the other two group (P=0.013, P=0.010), among which CD8+NaiveT was significantly higher In the other two groups (P=0.017), while CD8+TCM was higher than that in the other two groups, but without significant difference(P=0.064). The percentage of PD-1 expression in CD3+ T cells decreased from 44.05 (35.23-70.11) to 16.44 (6.07-35.42) after infection (P=0.028). Summary/Conclusion: Conclusions: The CRP, PCT, and IL-6 after infection were higher in the severe group than the other two groups. It takes more time for the result of covid-19 nucleic acid test to turn negative in the severe group. There is no difference in CT values among there groups when infection, but the severe group may be at an earlier post-transplantation stage than the mild group, and thus the number of immune cells is less than that of the other two groups. However, the percentages of NaiveT and TCM was higher in the severe group than those of the other two groups. Besides, the expression of PD-1 in T cells decreased after infection.Keywords: Allogeneic hematopoietic stem cell transplant